Through all of the political, economic and social changes made in the structure and function of western civilization its basic activities have remained unchanged.  The nuclei of civilized life have been cities concerned primarily with trade, commerce, industry, finance—­planned, organized and administered by businessmen, their professional and technical associates and assistants.  In practice, city centers of wealth and power have expanded, using the military as the readiest means of implementing policy.  They have occupied and garrisoned the foreign territory brought under their control.  At home and abroad they have exploited nature, men and other animals in their interest and for their profit.  The trading cities of medieval Europe, the emerging nations of the fifteenth and sixteenth centuries, the colonizing empires of the seventeenth and eighteenth centuries, and the industrial European empires of the nineteenth century devoted their energies increasingly to expanding into new territory, occupying and exploiting it, and fighting the wars which pock-marked the ceaseless struggle for pelf and power.  In short, they continued to build up the institutions and to follow the practices of civilized peoples.  This has been true of the millennium that began with the crusades and has hastened the rise of western civilization and its extension to planet-wide proportions.

Similar conclusions can be drawn from the life stories of the score or more of civilizations that rose, flourished and sank into inconsequence during the previous five thousand years.

Each civilization has had its own habitat, its own life pattern.  Each has had its own languages, laws, traditions and customs.  But despite such local differences, all of the civilizations have had in common those characteristics which justify their inclusion in the family of civilizations.

Anyone who wishes to test the accuracy of these generalizations may be satisfied by reading and observing the events that began with the wars between Japan, China and Russia, the Spanish American War, the Boer War, and the revolts in Cuba, China and the Philippines, all of which took place between 1895 and 1905.  The present century opened in a period of critical struggle between empires, within empires and between imperial centers and colonial dependencies.  These preliminary skirmishes led up to two general wars in 1914-1918 and 1936-1945, accompanied and followed by a score of minor wars and a planet-wide rash of civil wars and wars of independence waged by peoples of the erstwhile colonies.

Three johnnie-come-lately empires played star-roles in the drama:  Germany, the United States and Japan.  The histories of all three countries from 1870 to 1950 provide ample support for the contention that the central theme of western civilization, as of its predecessors, is a competitive struggle for wealth and power, aimed at expansion and exploitation, using war and the threat of war as instruments of policy.